1. Technical Field
The present invention relates to an optical cable, and more particularly, to a design for an all-dielectric self-supporting optical cable which is a type of an all-dielectric cable installed together with an extra-high voltage electrical power line.
2. Related Art
An overhead cable is installed along an aerial route using towers, poles, and structures of a building, for example. In the overhead cable, because weight of the overhead cable is concentrated to a securing portion on a structure, a method for supporting the overhead cable by a multitude of supporting wires can be used. In this case, most of the tension load which is generated due to the weight of the overhead cable is sustained by the multitude of wires. In the meanwhile, in the case of a composite fiber overhead ground wire (OHGW), a cable body can be structured in a manner such that it can sustain the tension load by itself.
I have found that a sheath of an all-dielectric self-supporting (ADSS) optical cable can be damaged under certain conditions. Efforts have been made to improve optical cables.
Exemplars of recent efforts in the art include U.S. Pat. No. 5,606,636 for optical cable for avoiding dri-band arcing, issued to Rowland et al.; U.S. Pat. No. 5,513,292 for overhead optical transmission system, issued to Rowland et al.; U.S. Pat. No. 5,526,457 for method and apparatus for preventing dry band arcing in a combined overhead electrical power and optical transmission system, issued to Rowland et al.; U.S. Pat. No. 5,230,034 for all dielectric self-supporting fiber optic cable, issued to Bottoms, Jr. et al.; U.S. Pat. No.5,325,457 for field protected self-supporting fiber optic cable, issued to Bottoms, Jr. et al.; U.S. Pat. No. 5,563,976 for semiconductive linear element including partially pyrolised polyacrylonitrile, issued to Rowland; and U.S. Pat. No. 4,155,963 for in-line manufacture of optical fibers cables with sequential laying, issued to de Vecchis et al.
While these recent efforts provide advantages, I note that they fail to adequately provide an improved all-dielectric self-supporting optical cable and manufacturing method thereof.
Accordingly, an object of the invention is to solve problems related to optical cables. A further object of the present invention is to provide an all-dielectric self-supporting (ADSS) optical cable and a manufacturing method thereof, in which a distal end of an armor rod is insulated by an insulating member, whereby a sheath of the all-dielectric self-supporting cable is prevented from being damaged by free electrons of the armor rod, when an electric field intensity between water droplets which are brought into electrification with the distal end of the armor rod by rainfall, dewdrops, etc. including ions due to a salty gradient and environmental pollution exceeds a dielectric breakdown strength of air, by the fact that an electric field at a dead end of the all-dielectric self-supporting cable is bent in a horizontal direction under the influence of a pylon, the ground and the dead end (including the armor rod) of the all-dielectric self-supporting cable.
In order to achieve the above objects and others, according to the present invention, there is provided an all-dielectric self-supporting optical cable installed on an extra-high voltage electrical power transmitting pylon, comprising: a first armor rod made of metal material and connected to a dead end of the all-dielectric self-supporting optical cable; and an insulating member for insulating the first armor rod.
According to another aspect of the present invention, there is provided a method for manufacturing all-dielectric self-supporting optical cable installed on an extra-high voltage electrical power transmitting pylon, the method comprising the steps of: connecting a dead end of the all-dielectric self-supporting optical cable and a first armor rod made of metal material with each other, thereby to connect the all-dielectric self-supporting optical cable to the extra-high voltage electrical power transmitting pylon; and insulating the first armor rod connected to the dead end of the all-dielectric self-supporting optical cable with an insulating member.
To achieve these and other objects in accordance with the principles of the present invention, as embodied and broadly described, the present invention provides an apparatus, comprising: an all-dielectric self-supporting optical cable being installed on an extra-high voltage electrical power transmitting pylon; a first armor rod including conducting material and being connected to an end of said all-dielectric self-supporting optical cable; an insulating member insulating said first armor rod; and a second armor rod including insulating material and surrounding said all-dielectric self-supporting optical cable by a predetermined length starting from an end of a portion of said all-dielectric self-supporting optical cable which is insulated by said insulating member.
To achieve these and other objects in accordance with the principles of the present invention, as embodied and broadly described, the present invention provides a method, comprising: manufacturing an all-dielectric self-supporting optical cable installed on an extra-high voltage electrical power transmitting pylon; connecting an end of said optical cable with a first armor rod including conductive material to connect said optical cable to the pylon; and insulating said first armor rod connected to said end of said optical cable with an insulating member.
To achieve these and other objects in accordance with the principles of the present invention, as embodied and broadly described, the present invention provides an apparatus, comprising: an all-dielectric self-supporting optical cable being installed on an extra-high voltage electrical power transmitting pylon; a first armor rod including conducting material and being connected to an end of said all-dielectric self-supporting optical cable; an insulating member insulating said first armor rod; and a second armor rod including insulating material and surrounding a predetermined length of said optical cable.
The present invention is more specifically described in the following paragraphs by reference to the drawings attached only by way of example. Other advantages and features will become apparent from the following description and from the claims.